Field of the Invention
The invention relates to an illuminated seat belt buckle for a seat belt, in particular of a motor vehicle, comprising a buckle housing, a locking mechanism, an insertion slot for a belt latch of the seat belt, an actuating button for release purposes and comprising an illuminating device which has at least one light source and is arranged in the buckle housing.
Description of the Background Art
A seat belt provided for restraining the body of a vehicle occupant is usually fastened by inserting a belt latch connected to the seat belt into an insertion slot of a seat belt buckle and locking it in the seat belt buckle with the aid of a locking mechanism. An actuating button is provided on the belt buckle for release purposes. In the dark, it is difficult for the vehicle occupant to locate the insertion slot of the seat belt buckle in order to insert the belt latch into the seat belt buckle. For this reason, different approaches have already been proposed, in which an illuminating device is built into the seat belt buckle so that the insertion slot of the seat belt buckle accommodating the belt latch is illuminated in the dark.
For example, a seat belt buckle having an illuminating device for locating the insertion slot for the belt latch is already known from DE 10 2011 114 538 A1, which corresponds to U.S. 20140268844. The illuminating device arranged in the buckle housing comprises a light source and a light conductor. The light conductor, which receives and distributes the light generated by the light source, is arranged in the insertion slot in such a way that a reflecting surface on the front of the light conductor terminates flush with the buckle housing. The reflecting surface of the light conductor is thus visibly arranged in the insertion slot of the seat belt buckle. The light conductor runs from the front reflecting surface in the direction of the light source in a wedge-like manner.
It has proven to be disadvantageous that the illuminating device comprising the light source and the light conductor is arranged directly in the area of the seat belt buckle, into which the belt latch is to be inserted. Damage to the illuminating device may thereby occur when the belt latch is inserted into the seat belt buckle. The arrangement of the reflecting surface of the light conductor, visible to the vehicle passenger, results in a direct, inhomogeneous and not particularly high quality illumination of the insertion slot. Moreover, due to the arrangement of the light conductor and the light source in the area of the insertion slot, the interior of the seat belt buckle is also illuminated, so that the vehicle occupant is able to see the details of the locking mechanism, including any dirt that may be present in the buckle interior. Additional installation space, which is already in short supply, in particular in the area of the insertion slot, must also be made available for the illuminating device. When the belt latch is situated and locked in the seat belt buckle, the light conductor of the illuminating device is almost completed covered by the belt latch itself and by the seat belt connected to the belt latch, so that the reflecting surface of the light conductor is not visible to the vehicle occupant. The illuminating device is therefore used exclusively to locate the seat belt buckle during an insertion of the belt latch but not to locate the seat belt buckle or the actuating button when releasing the belt latch.